This invention relates generally to the production of solid sugar surfactants and more particularly to an extraction process for the production of solid alk(en)yl oligoglycosides.
By virtue of their excellent performance properties and their high ecotoxicological compatibility, alk(en)yl oligoglycosides are important basic raw materials, for example for the production of cosmetic preparations or manual dishwashing detergents. These surfactants are normally processed in the form of water-containing pastes although, for a number of applications, for example the production of bar soaps or detergents, there is also a particular interest in solid preparations which are easier to process and do not first have to be freed from unwanted water.
Various processes for the production of such solid sugar surfactants are known from the prior art. For example, WO 97/03165 (Henkel) describes the simultaneous drying and granulation of zeolite-containing sugar surfactant pastes in a fluidized bed. International patent applications WO 97/10324 and WO 98/40460 (Henkel) describe the removal of water from sugar surfactant pastes in a horizontal thin-layer evaporator.
Unfortunately, these processes are of little interest on economic grounds because they involve considerable outlay on equipment. Accordingly, the problem addressed by the present invention was to provide a simplified process for the production of solid sugar surfactants which, in particular, would not involve the removal of excess fatty alcohol by distillation.